In a solar cell, an electrode is provided on a photoelectric conversion section for efficiently extracting carriers, which are generated in the photoelectric conversion section having a semiconductor junction, to an external circuit. In a heterojunction solar cell including on a crystalline silicon substrate a semiconductor layer composed of a silicon-based thin-film, a transparent electrode layer and a metal collecting electrode are provided as electrodes, and a patterned collecting electrode is provided on the light incident side. The electrode in the solar cell is connected to a wiring member, and the wiring member is electrically connected to the adjacent solar cell or the external circuit to perform modularization.
In formation of a photoelectric conversion section of a heterojunction solar cell, thin-films such as a semiconductor layer, a transparent electrode layer and a metal electrode are generally formed on the silicon substrate surface by a dry process such as a plasma-enhanced CVD method, a sputtering method or the like. These thin-films exist not only on the front surface of a substrate, but also on the side surface and on the back surface since the deposited films wrap around thereon, and thereby cause a short circuit and leakage current between the front surface and the back surface.
Patent Document 1 suggests a method in which a semiconductor layer and an electrode layer are formed while a peripheral portion of a crystalline silicon substrate is covered with a mask for preventing an electrical short-circuit and leakage resulting from wraparound of a thin-film. Patent Document 2 suggests a method in which after formation of a semiconductor layer and an electrode layer, a peripheral portion of a crystalline silicon substrate is cleaved and removed to form a side surface of a photoelectric conversion section into a cut surface to which the silicon substrate is exposed. Patent Document 3 suggests a method in which a cell peripheral portion is irradiated with laser light to form a separation groove, and a transparent electrode layer and a semiconductor layer on a crystalline silicon substrate are removed. For the cut surface in Patent Document 2 and the separation groove in Patent Document 3, an electrode and a semiconductor layer do not exist on the surface, and thus a silicon substrate is exposed, so that a short-circuit part resulting from wraparound is removed.